Process of treating filaments and yarns of thermoplastic addition polymers



United States Patent 3,094,718 PROCESS OF TREATING FlLAMENTS AND YARNS OF TIERMOPLASTIC ADDITION POLYMERS Stephen Bernard Robinson, Jr., Moorestown, NJ., assignor to Rohm & Haas Company, Philadelphia, Pa., a corporation of Delaware No Drawing. Filed Mar. 9, 1960, Ser. No. 13,731 14 Claims. (Cl. 8--155) The present invention is concerned with a process for the modification of thermoplastic filaments or yarns thereof formed of linear addition polymers having an apparent second order transition temperature, herein designated T of about 40 to 125 C. or higher. The modification contemplated is one involving chemical reaction with the filamentous material so as to modify its physical characteristics such as its hand, dyeability, moisture-regain, resistance to shrinkage, stabilization against shrinkage on Washing or scouring, or to introduce ion-exchange groups of either cationor anion-exchange types. The invention is particularly concerned with processes involving chemical modification of the linear polymeric fiber or yarn by a treatment which involves subjecting the filamentous material to an elevated temperature appreciably above the apparent second order transition temperature as defined hereinafter. The modification generally requires application of a separate reactant; and the heating step may occur prior to, during, or after impregnation or other application of a chemical re-agent which serves to modify the filamentous material by reaction therewith.

The apparent second order transition temperature, here symbolized as T is defined as that temperature at which the first derivative of thermodynamic variables, such as coefficient of expansion or heat capacity, undergoes a sudden change. The transition temperature is observed as an inflection temperature which is conveniently found by plotting the log of the modulus of rigidity against temperat-ure. A suitable method for determining such modulus and transition temperature is described by Williamson in British Plastics 23, 87-90. The T, values here used are generally those temperatures at which the modulus is 300 kg./cm. The T, values referred to are for polymers as such in a dry state unless otherwise designated.

Such treatments have been applied to skeins of such fibers, but it has frequently been found that the fibers become coalesced or cemented to one another during the heat treatment when such heat treatment occurs at a temperature substantially above the T value of the polymer of which the fiber is constituted. In order to prevent such cementation, attempts have been made to form windings with separated coils including non-adherent separating strips of thin cardboard or heavy kraft paper or the like between the layers of the windings. In addition,

silicone oils have been applied after application of the chemical reagent and before the heating operation in an attempt to overcome the difliculty with cementation.

In accordance with the present invention, it has now been found that the chemical modification including the step of subjecting the fibrous material to elevated temperatures above the T value of the material can be effected without cementation when the treatment is applied to the fibers, filaments, or yarns while they are wound so that the windings in the bobbins are close together and form a compact package or body. It is surprising that treatment of such a tightly wound body wherein the yarns are in contact with each other does not aggravate the cementation tendencies. In an attempt to rationalize this unexpected and surprising effect, it is theorized that the cementation is caused by a solvation and swelling of the individual fibers by the liquid medium containing the reagent or remaining in the bobbin after impregnation with Patented June 25, 1963 ice 2- the re-agent and through the heat treating stage and this swelling or solvation is prevented or limited by the compactness of the windings which prevents the entry or limits the entry of excess amounts of the liquid media into contact with the fibers of the winding.

The treatment of the fibers or yarns in the form of a wound bobbin also has the effect of maintaining the fibers under tension so that they cannot shrink appreciably dur ing the treatment. This is particularly important in the treatment of fibers in which the molecules of polymer are oriented to a substantial extent in the direction of the axis of the fiber. By maintaining the fibers in taut condition during the treatment and especially during the heat treatment, shrinkage and loss of orientation as well as loss in tensile strength are avoided.

The linear addition polymers with which the present invention is concerned may be homopolymers or copolymers formed of one or more monoethylenically unsaturated compounds, such as esters of acrylic or methacrylic acid with alcohols having 1 to 10 carbon atoms, vinyl ethers or esters such as vinyl chloride, vinyl acetate, vinyl methyl ether, acryl-onitrile, acrylamide, vinylidene chloride, styrene, butadiene, and the like. The processes of chemical modification contemplated by the present invention are those involving the cross-linking of such linear polymers by reaction with polyfunctional and particularly difunctional re-agents. It also contemplates the treatment with agents whichserve to convert units in the polymer into modified units including amine units for the purpose of improving dye-ability; hydroxyl or carboxyl units to increase the hydrophilicity of the polymer; and the introduction of thiol, carboxyl, amine, quaternary ammonium, and sulfonic acid units, or salts of any of these units for the purpose of producing ion-exchange fibers.

The linear polymers thus may include units adapted to be cross-linked. The monomers which provide the crosslinkable units in the coplymer include glycidyl acrylate and methacrylate, ureidoalkyl esters, such as ureidoethyl acrylate .and methacrylate, ureidoethyl vinyl ether, ureidopentyl vinyl ether, ureidoisobutyl vinyl ether, N-vinylo-xyalkyl carbamates, such .as N-B-vinyloxyethyl carbarnate, acrylamides, methacrylamides, N-mono-substituted acrylamides and methacrylamides, such as acrylamide per se, methacrylarnide per se, N-methylor N-ethyl acrylamide or metha'crylamide, hydroxyethyl vinyl ether or sulfide, hydroxypentyl vinyl ether or sulfide, 2-isocyanato vinyl ethers, such as 2-isocyanatow2,'2-dirnethylethyl vinyl ether, aminoalkyl acrylates and methacrylates, such as aminoethyl acrylate, dimethylaminoethyl acrylate and N-dimethylaminoethyl acrylamide, alkoxymethyl vinyl sulfides, such as methoxymethyl vinyl sulfides, alkoxymethyl thioalkyl acrylates, methacrylates, and itaconates, such as methoxymethylthioethyl acrylate. In general, the cross-linkable monomer is a monoethylenically unsaturated compound containing a reactive substituent, such as carboxyl, hydroxyl, amido, amino, epoxy, isocyanato, or ureido groups, and the like.

When the polymer contains epoxy groups, as in the case-of copolymers of glycidyl acrylate or methacrylate, the cross-linking may be efiected by reacting with polyamines containing atleast two primary, secondary, or tertiary aminenitrogen atoms at a temperature from 50 C. to 250 C., the upper limit being dependent upon the other comonomers present and being insufliciently high to destroy the fiber structure. The time generally used is inversely proportional to the temperature. For example, a period of a few secondsto 15 seconds may be proper in the upper regions of the temperature range given, whereas a period of time of a half an hour to sev-. eral days maybedesirable at lower temperatures in the range cited. It is believed that the cross-linking action obtained with the polyamines when they contain tertiary amine nitrogen groups is attributable to quaternization. The diamine may be applied in a solvent, such as Water, at a concentration of to but when it is a liquid it may be applied directly without dilution in a solvent. The fibers "may be impregnated with the diamine by simple immersion or by spraying, or in any other suitable manner. Examples of polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, N,N-dimethyl-ethylenediamine, N,N, N,N' tetramethyl ethylenediamine, N,N,N',N tetraethyl-ethylenediamine, and N,N,N,N' tetraethyl hexamethylenediarnine.

When the cross-linkable units of the polymer contain ureido or carbamato groups or linkages, cross-linking may be effected by reaction with aldehydes, especially formaldehyde, or by urea or methylol derivatives of urea, such as dimethylol urea. For this purpose, the formah dehyde or urea or derivatives of urea may be applied from solutions in water or alcohol, and the impregnated structure is heated to effect cross-linking at temperatures ranging from 50 to 250 C. for times of the same general range as outlined hereinabove in respect to the crosslinking of polymers of glycidyl acrylates with polyamines. Besides aldehydes, polyisocyanates or polyisothiocyanates, such as toluene-2,4-diisocyanate, hexamethylenediisocyanate, and the like may be used for efiecting crosslinking. With them, temperatures from 50 C. up to 250 C. may be employed, depending upon the particular polyisocyanate and the particular polymer. The times may be as above, in any case the time employed being suificient to give the desired cross-linking.

When the cross-linkable groups in the polymer are isocyanate groups, the cross-linking may be efiected by any compound having at least two reactive hydrogen atoms, including aldehydes, polyamines, such as those mentioned hereinabove for cross-linking the polymers of glycidyl acrylates, polyhydric alcohols, such as glycols, including ethylene glycol, diethylene glycol, hexamethylene glycol, glycerol, sorbitol, sorbitan, and sorbide, polythiols, especially the dithiols such as ethylene dithiol, pxylylene dithiol, p-olyhydroxyphenols, such as resorcinol, pyrocatechol, orcinol, tannic acid, polycarboxylic acids, and especially dicarboxylic acids, such as succinic acid, adipic acid, sebacic acid, o-phthalic acid, terephthalic acids, and so on. Treatment may be efiected by immersion or spraying in the polyfunctional reactant if it is a liquid or molten at the temperature employed, or by immersion or spraying of a solution of the polyfunctional reactant. The heating may be elfected while the polymeric structure is immersed in the body of reagent, but preferably excess reagent is removed and the polymer structure is heated at temperatures from about 50 C. up to 100 C. or more, such as up to 200 C. for a sufiicient time to efiect cross-linking which may amount to a few seconds at the high temperature up to a quarter of an hour or more at the lower temperature of the range.

When the cross-linkable units in the polymeric structures contain amine groups, cross-linking may be effected by polycarboxylic acids or polyisocyanates, such as any of those mentioned above, and the reaction may be effected at the temperatures mentioned hereinabove. When the cross-linkable units contain amine groups having tertiary nitrogen atoms, the cross-linking may be efiected by quaternization by means of poly-halides and especially di-halides, including ethylene dichloride, xylylene dichloride, hexamethylene dichloride.

When the cross-linkable units contain hydroxyl groups, the cross-linking may be effected by means of aldehydes, such as formaldehyde, acetaldehyde, glyoxal, and the like; also aldehyde derivatives of urea, such as dimethylol urea, reaction being efrected at temperatures of about 50 C. to 250 C. for periods of an hour at the lower temperature to a few seconds at the higher temperatures.

Besides aldehydes and their derivatives, cross-linking may be efiected by polyisocyanates or polyisothiocyanates, such as those mentioned hereinabove, polycarboxylic acids, such as those mentioned hereinabove, and by polybasic acid halides, such as succinyl chloride, adipyl chloride, and so on. These reactions may be eflected within the temperature ranges mentioned hereinabove and in similar time periods.

The cross-linkable units of the polymer may consist of alkoxymethyl vinyl sulfide units, and especially methoxymethyl vinyl sulfide, which can be converted to thiol units by hydrolysis and the thiol units then converted to disulfide linkages by mild oxidation. The alkoxymethyl vinyl sulfide compounds that may be used as monomers have the structure of Formula I:

CHFCQR) SR'OR" (I) where R is selected trom the group consisting of hydrogen and methyl,

R is a methylene, ethylidene, or isopropylidene group,

and

R is an alkyl group having 1 to 8 carbon atoms, but is preferably methyl.

Since part or all of the -ROR" portion of the compound is eliminated in the subsequent cross-linking, it is generally preferred to polymerize the simplest compound, namely the methoxymethyl vinyl sulfide, in preparing the polymers to be used in making the fibers.

The polymer product may be treated with a solution of the oxidizing agent at any temperature from about 60 C. up to about 180 C. or higher for various periods of time. For example, the treatment may be effected for about 10 seconds to 15 minutes at about C. The permissible upper limits of the conditions of temperature, time, and concentration depend on the individual oxidizing agents and they are correlated to provide a mild oxidation which serves to effect cross-linking, but does not go appreciably further to form substantial amounts of sulfone and sulfonic acid groups. The upper limit of concentration depends on the individual agent and the temperature at which the oxidation is carried out.

In many cases, it may be desirable to carry out the main part of the heating to effect the cross-linking after a relatively limited period of treatment in a solution of the oxidant which serves primarily to effect impregnation of the fiber, filament bundle or the like with the oxidant and may or may not serve to efiect a portion of the desired cross-linking. The subsequent heating stage in such event may be termed a baking or curing step and may be carried out at temperatures of 50 C. to 200 C. but, as discussed hereinbefore, the upper limit of temperature in this stage is dependent on the particular oxidant employed. In such cases, after removal of the polymer product from the medium containing the oxidizing agent, the excess of such medium may be removed as by suction or air-squeegeeing and the oxidation which may or may not have been started while the polymer product is immersed in the medium containing the oxidizing agent may be pushed to completion by subsequently heating the polymer product at elevated temperatures from about 80 C. to 200 C. for a period of time ranging from about 5 minutes to about half an hour at the higher temperature to about 15 minutes to about an hour or two at the lower temperature.

The cross-linkable units of the polymer may consist of alkoxymethylthiolalkyl acrylate, methacrylate, or itaconate units. These units are hydrolyzed to thiol groups in the same manner as the alkoxymethyl vinyl sulfide units hereinbefore described and mild oxidation as described above serves to form disul-fide linkages.

Among the processes for modification of the linear polymer are procedures for hydrolyzing ester units in the polymer such as acrylates, particularly methyl acrylate, and vinyl acetate to introduce acid or hydroxyl groups respectively. Acryl'onitrile polymers may likewise be hydrolyzed to introduce amide and acid units. Polymers comprising units of esters of acrylic or methacrylic acid or of other acids may be aminolyzed by reaction with an amine or a diamine such as diethanolamine or N,N-dimethylaminoethylamine for the purpose of introducing basic amine groups in the copolymer. The treatment may also involve alkylation of polymers containing amine groups to produce quaternary ammonium compounds. All of these treatments may be effected at temperatures of 50 C. up to 130 C. or even in some cases up to 200 C. so that the present process is of advantage in these treatments as it enables the treatment to be carried out at temperatures which may be higher than the apparent second order transition temperature of the fiber.

In general, release-agents such as silicone oils are not. necessary to' assure complete freedom from cementa tion. However, such oils may be used if desired.

The chemical re-agent which serves to modify the fiber may be applied in liquid medium consisting entirely of the re-agent if such re-agent is liquid at the temperature of application or as a solution or dispersion in either aqueous or organic solvent media. Application may be effected by spraying, immersion, soaking, or by forcing the liquid treating media through the windings of the bobbin by means of an internal perforated core into which the liquid medium may be forced under pressure so that it permeates from the core through the entire body of the winding. The bobbin or plurality thereof may be mounted on such perforated core within an enclosed drum or chamber so that the liquid flow may be. alternately forced to proceed from the interior of the core through the winding or from the space in the chamber through the winding and out through the perforated core.

The wound bobbin may be subjected to the heat treatment during the impregnation with the liquid medium and for this purpose, the liquid medium may itself be heated and/ or the vessel containing the bobbins may be heated externally by means of a steam jacket. Alternatively, the winding may be preheated by being subjected to a hot gas such as hot air or an inert gas such as hot nitrogen or carbon dioxide before it is impregnated. Again, the heat treatment may be performed after the impregnation such as in a baking or curing operation. In this case, the impregnated bobbin may be removed from the impregnating medium, excess being removed by squeegeeing, vibrating, and then the bobbins are subjected to the heat treatment as in a baking or curing operation in an oven or under the influence of any other suitable heating equipment. The procedure involving impregnation and subsequent subjection to heat has the advantage of favoring completely uniform distribution of the impregnating liquid including the reagent before appreciable reaction is effected.

The following examples are illustrative of the invention and the parts and percentages are by weight unless otherwise specifically indicated.

Example 1 A yarn formed of a polymer of 70 parts of acrylonitrile, 10 parts of butoxyethyl acrylate, and 20 parts of methoxymethyl vinyl sulfide which has been stretched about 600% during its formation is wound on a bobbin under a tension of about 2 grams per denier. The bobbin is then treated by soaking in 4% aqueous phosphoric acid for one hour at 40 'C., and then treated with a solution of 5% iodine in ethanol at 40 C. for one hour. The yarn is withdrawn from the solution, excess iodine solution is removed, and the yarn is then cured by heating it on the bobbin at 150 C. for 40 minutes. It has a tensile strength of 3.0 grams. per denier and an extensibility at break of 28%. The temperature at which the yarn shows 5% shrinkage is 150 C. It. shrinks solution, and subsequent heating shows 5% shrinkageat C. and shrin-gs 75% on being heated to 200 C.

Example 2 A yarn formed of a copolymer of 65 parts of acrylo nitrile, 15 parts of butoxyethyl acrylate, and 20 parts of methoxymethyl vinyl sulfide which had been stretched 600% during its initial formation is wound at a tension of about 1 /2 grams per denier into a compact bobbin on a perforated core. The wound bobbin is soaked in aqueous 4.9% phosphoric acid for 30 minutes at 40 C. The. yarn is then soaked for ten minutes in an aqueous solution containing 0.04% NaOH and 1% iodine, the pH of which is adjusted to 9.0 with N/2. H the temperature of this solution being 40 C. The yarn is then heated at 150 C. for one hour.

The yarn, which is now cross-linked in an oriented state, is then treated with 140 milliliters per gram of a mixture of 50 parts of N/ZO sodium hydroxide in water and 50 parts of ethanol at the refluxing temperature of the mixture for two days to hydrolyze some of its units to carboxylic groups. The resulting product is a carboxylic ion-exchange material in the form of a yarn, the filaments of which show orientation along the fiber axis and have a capacity for exchanging sodium of 3.2 milliequivalents per gram.

Example 3 (a)- A yarn comprising fibers formed of a copolymer of 70% acrylonitrile, 25% ethyl acrylate, and 5% ureidopentyl vinyl ether, which has been stretched about 250% during its formation, is wound on a bobbin at a tension of about 1 gram per denier and the bobbin is soaked in toluene-2,4-diisocyanate at 25 C. for two minutes and heated at 70 C. for 40 hours. The cured yarn is then hydrolyzed with a solution of sodium hydroxide in water and ethanol in the manner described in Example 2. The product has a capacity for exchanging sodium of about 3 milliequivalents per gram.

(b) In the same way, a cation-exchange fiber is obtained by subjecting a yarn comprising fibers formed of 65% of acrylonitrile, 25% of methyl acrylate, and 10% of hydroxypentyl vinyl ether, wound in the form of a bobbin under a tension of about 1.5 grams per denier, to the same treatment as just described.

Example 4 A yarn comprising filaments formed of a copolymer of 45% ethyl acrylate, 35% acrylonitrile, and 20% glycidyl methacrylate, which has been stretched about 150% during formation, is wound into a bobbin under a tension of about 1.5 grams per denier. The bobbin is then, soaked in an aqueous 20% solution of hexamethylenediamine for hours at 25 C. The soaked yarn is removed from the solution and allowed to dry in the air to eliminate excess surface moisture and is then heated at 80 C. for one hour, followed by subjection to C. for one hour. It is then washed in 5% aqueous acetic acid solution at 25 C., washed with water, and air-dried.

The bobbin may then be treated by soaking in a 50:50 volume mixture of N/ 20 sodium hydroxide and ethanol at 60 C. for about two days. Yarn obtained in this fashion.

has a cation-exchange capacity of about 2 milliequivalents per gram.

Example 5 is forced and recirculated a solution comprising a 50:50

weight ratio mixture of dimethylaminopropylamine and dodecane at C. for one hour. Thereafter, there is- '5? forced through the bobbin by Way of the perforated core a solution of 20% p-Xylylene dichloride in toluene .at 50 C. Thereafter, the bobbin is cured by heating at 150 C. for 30 minutes.

(11) A bobbin prepared in this fashion may then be impregnated with a mixture in 60:40 volume ratio of N/20 sodium hydroxide and ethanol for about 24 hours at 60 C. Yarn obtained in this fashion has .a cation-exchange capacity of about 2 to 2.5 milliequivalents per gram.

Example 6 The procedure of Example (a) is repeated except that the p-xylylene dichloride solution is replaced with a solution of 10% of p-Xylylene dichoride and benzyl chloride in toluene. The resulting anion-exchange fibers can be converted into sulfate form by soaking the bobbin in 5% sulfuric acid.

I claim:

, 1. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium comprising an agent for modifying the polymer by chemical reaction, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect chemical modification of the polymer in the fiber.

2. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive groups which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium comprising a polyfunctional reagent having groups which react with the reactive groups of the polymer, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

3. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive groups selected from the group consisting of carboxyl, hydroxyl, amido, amino, epoxy, isocyanato, and ureido groups, which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium comprising a polyfunctional reagent having groups which react with the reactive groups of the polymer, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

4. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive ureido groups which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium containing an organic polyisocyanate, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

5. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive hy droxyl groups which comprises the step of winding a yam of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium containing an organic polyisocyanate, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

6. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive glycidyl groups which comprises the step of winding 21 yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium containing a polyamine, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

. 7. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing reactive amino groups which comprises the step of winding 21 yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium containing an organic dihalide, and then heating the impregnated bobbin to a temperature which is above the apparent second order transition temperature of the polymer and is at least 50 C. in order to effect cross-linking of the polymer in the fiber.

8. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer having an apparent second order transition temperature of 40 C. up to 200 C. and containing hydrolyzable alkoxymethylthio groups which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium comprising an acid to hydrolyze the alkoxymethylthio groups to thiol groups, impregnating the bobbin with a solution of iodine and then heating the iodine-impregnated bobbin to form disulfide cross-linkages between the linear polymers in the fiber.

9. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer of at least one monomer selected from the group consisting of the nitrile, amide, and ester derivatives of an acid selected from the group consisting of acrylic acid and methacrylic acid, having an apparent second order transition temperature of 40 C. up to 200 C. which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid alkaline medium, and heating the impregnated bobbin to hydrolyze the acid derivative to introduce carboxylate salt groups into the polymer.

10. A process for chemically modifying a filamentous material formed of a thermoplastic linear addition polymer of at least one monomer selected from the group consisting of the nitrile, amide, and ester derivatives of an acid selected from the group consisting of acrylic acid and methacrylic acid, having an apparent second order transition temperature of 40 C. up to 200 C. which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid medium containing a diamine having a tertiary nitrogen atom'and a nitrogen atom having at least one hydrogen atom attached thereto, and heating the impregnated bobbin to aminolyze the acid derivative to introduce amino groups into the polymer.

11. A process according to claim 10 comprising the additional steps of impregnating the bobbin of fiber containing aminolyzed polymer with a liquid medium containing a quaternizing material and heating the impregnated bobbin to effect quaternization of tertiary amine groups in the polymer.

12. A process according to claim 10 comprising the additional steps of impregnating the bobbin of fiber containing aminolyzed polymer with a liquid medium containing a difunctional quaternizing material and heating the impregnated bobbin to eflect quaternization of tertiary amine groups in the polymer and thereby cross-linking the polymer, then impregnating the bobbin with a liquid alkaline medium and heating the impregnated bobbin to hydrolyze the acid derivative to introduce carboxylate salt groups into the polymer.

13. A process according to claim 11 in which the qua ternizing material includes a difunctional quaternizing agent to efiect cross-linking of the polymer molecules by reaction with tertiary amine groups therein.

14. A process for chemically modifying a filamentous material formed of a cross-linked addition polymer of at least one monomer selected from the group consisting of the ni-trile, amide, and ester derivatives of an acid selected from the group consisting of acrylic acid and methacrylic acid, which comprises the step of winding a yarn of such filamentous material into a compact bobbin, impregnating the bobbin with a liquid alkaline medium and heating the impregnated bobbin to hydrolyze the acid derivative to introduce carboxylate salt groups into the polymer.

References Cited in the file of this patent UNITED STATES PATENTS 2,090,862 Etkorn Aug. 24, 1937 2,093,140 Schieber Sept. 14, 1937 2,325,060 Ingersoll July 27, 1943 2,786,732 Gabler Mar. 26, 1957 2,926,062 Gagliardi Feb. 23, 1960 3,022,926 Bailey Feb. 27, 1962 

1. A PROCESS FOR CHEMICALLY MODIFYING A FILAMENTOUS MATERIAL FORMED OF A THERMOPLASTIC LINEAR ADDITION POLYMER HAVING AN APPARENT SECOND ORDER TRANSITION TEMPERATURE OF 40*C. UP TO 200*C. WHICH COMPRISES THE STEP OF WINDING A YARN OF SUCH FILAMENTOURS MATERIAL INTO A COMPACT BOBBIN, IMPREGNATING THE BOBBIN WITH A LIQUID MEDIUM COMPRISING AN AGENT FOR MODIFYING THE POLYMER BY CHEMICAL REACTION, AND THEN HEATING THE IMPREGNATED BOBBIN TO A TEMPERATURE WHICH IS ABOVE THE APPARENT SECOND ORDER TRANSITION TEMPERATURE OF THE POLYMER AND IS AT LEAST 50*C. IN ORDER TO EFFECT CHEMICAL MODIFICATION OF THE POLYMER IN THE FIBER. 